Wavelength modulation photoacoustic spectroscopy using a near-infrared DFB diode laser

2020 ◽  
Author(s):  
Qi Huang ◽  
Wangxuan Zhao ◽  
Sheng Zhou ◽  
Jingsong Li
Keyword(s):  
Diode Laser ◽  
Photoacoustic Spectroscopy ◽  
Near Infrared ◽  
Wavelength Modulation

scholarly journals High Sensitivity Continuous Monitoring of Chloroform Gas by Using Wavelength Modulation Photoacoustic Spectroscopy in the Near-Infrared Range

2021 ◽  
Vol 11 (15) ◽  
pp. 6992
Author(s):  
Tie Zhang ◽  
Yuxin Xing ◽  
Gaoxuan Wang ◽  
Sailing He
Keyword(s):  
Photoacoustic Spectroscopy ◽  
Continuous Monitoring ◽  
Near Infrared ◽  
Resonant Cavity ◽  
High Sensitivity ◽  
Industrial Applications ◽  
Detection Sensitivity ◽  
Infrared Range ◽  
Wavelength Modulation ◽  
Linear Coefficient

An optical system for gaseous chloroform (CHCl3) detection based on wavelength modulation photoacoustic spectroscopy (WMPAS) is proposed for the first time by using a distributed feedback (DFB) laser with a center wavelength of 1683 nm where chloroform has strong and complex absorption peaks. The WMPAS sensor developed possesses the advantages of having a simple structure, high-sensitivity, and direct measurement. A resonant cavity made of stainless steel with a resonant frequency of 6390 Hz was utilized, and eight microphones were located at the middle of the resonator at uniform intervals to collect the sound signal. All of the devices were integrated into an instrument box for practical applications. The performance of the WMPAS sensor was experimentally demonstrated with the measurement of different concentrations of chloroform from 63 to 625 ppm. A linear coefficient R2 of 0.999 and a detection sensitivity of 0.28 ppm with a time period of 20 s were achieved at room temperature (around 20 °C) and atmosphere pressure. Long-time continuous monitoring for a fixed concentration of chloroform gas was carried out to demonstrate the excellent stability of the system. The performance of the system shows great practical value for the detection of chloroform gas in industrial applications.

Near-infrared diode laser wavelength modulation-based photoacoustic spectrometer

2006 ◽  
Vol 64 (2) ◽  
pp. 338-342 ◽  
Author(s):  
Jingsong Li ◽  
Xiaoming Gao ◽  
Weizheng Li ◽  
Zhensong Cao ◽  
Lunhua Deng ◽  
...  
Keyword(s):  
Diode Laser ◽  
Near Infrared ◽  
Laser Wavelength ◽  
Wavelength Modulation ◽  
Photoacoustic Spectrometer

Photoacoustic spectroscopy telemetry of airport dangerous goods

2019 ◽  
Vol 33 (02) ◽  
pp. 1950007
Author(s):  
Zhouqiang Zhang ◽  
Shuhai Jia ◽  
Guangshen Xu ◽  
Yabin Cao
Keyword(s):  
Absorption Coefficient ◽  
Diode Laser ◽  
Infrared Absorption ◽  
Photoacoustic Spectroscopy ◽  
Near Infrared ◽  
Tuning Fork ◽  
Laser Light ◽  
Quartz Tuning Fork ◽  
Dangerous Goods ◽  
Future Work

A novel photoacoustic spectroscopy telemetry method of detecting trace acetylene gas using a quartz tuning fork is reported. A 1532-nm CW-DFB, fiber-coupled diode laser with power of 12 mW was used as the excitation source while an astronomical telescope was used to collect laser light scattered on the surface of the detected object at a distance of 6 m and the photoacoustic spectroscopy of acetylene was performed. The detection results are consistent with the standard near-infrared absorption coefficient of acetylene. This study provides a new direction for research in photoacoustic spectroscopy telemetry. Future work will quantitatively analyze acetylene gas.

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